USA.gov has recently been updated with Data.gov as a part of the Data and Statistics – General Reference Resources page. The following is the stated purpose:
The purpose of Data.gov is to increase public access to high value, machine readable datasets generated by the Executive Branch of the Federal Government.
Data.gov includes a searchable data catalog that includes access to data in two ways: through the “raw” data catalog and using tools.
The Primary Goal of this site reads as follows:
A primary goal of Data.gov is to improve access to Federal data and expand creative use of those data beyond the walls of government by encouraging innovative ideas (e.g., web applications). Data.gov strives to make government more transparent and is committed to creating an unprecedented level of openness in Government. The openness derived from Data.gov will strengthen our Nation’s democracy and promote efficiency and effectiveness in Government.
Users may also suggest other data and materials to be added to this page and the searchable database.